fix(no-deprecated-functions): use latest jest version if no version detected

src/rules/__tests__/no-deprecated-functions.test.ts

@@ -1,18 +1,12 @@
-import { TSESLint } from '@typescript-eslint/utils';
+import type { TSESLint } from '@typescript-eslint/utils';
 import rule from '../no-deprecated-functions';
-import {
-  type JestVersion,
-  detectJestVersion,
-} from '../utils/detectJestVersion';
-import {
-  FlatCompatRuleTester as RuleTester,
-  usingFlatConfig,
-} from './test-utils';
+import { type JestVersion, getJestVersion } from '../utils/detectJestVersion';
+import { FlatCompatRuleTester as RuleTester } from './test-utils';
 
 jest.mock('../utils/detectJestVersion');
 
-const detectJestVersionMock = detectJestVersion as jest.MockedFunction<
-  typeof detectJestVersion
+const getJestVersionMock = getJestVersion as jest.MockedFunction<
+  typeof getJestVersion
 >;
 
 const ruleTester = new RuleTester();
@@ -67,11 +61,6 @@ describe('the rule', () => {
     valid: [
       { code: 'jest', settings: { jest: { version: 14 } } },
       { code: 'require("fs")', settings: { jest: { version: 14 } } },
-      ...generateValidCases(14, 'jest.resetModuleRegistry'),
-      ...generateValidCases(17, 'require.requireActual'),
-      ...generateValidCases(25, 'jest.genMockFromModule'),
-      ...generateValidCases('25.1.1', 'jest.genMockFromModule'),
-      ...generateValidCases('17.2', 'require.requireActual'),
     ],
     invalid: [
       ...generateInvalidCases(
@@ -90,14 +79,53 @@ describe('the rule', () => {
         'jest.genMockFromModule',
         'jest.createMockFromModule',
       ),
+      ...generateInvalidCases(
+        14,
+        'jest.resetModuleRegistry',
+        'jest.resetModules',
+      ),
+      ...generateInvalidCases(
+        17,
+        'require.requireActual',
+        'jest.requireActual',
+      ),
+      ...generateInvalidCases(
+        25,
+        'jest.genMockFromModule',
+        'jest.createMockFromModule',
+      ),
+      ...generateInvalidCases(
+        '25.1.1',
+        'jest.genMockFromModule',
+        'jest.createMockFromModule',
+      ),
+      ...generateInvalidCases(
+        '17.2',
+        'require.requireActual',
+        'jest.requireActual',
+      ),
     ],
   });
 
-  describe.each<JestVersion>([
-    14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27,
+  describe.each<ReturnType<typeof getJestVersion>>([
+    14,
+    15,
+    16,
+    17,
+    18,
+    19,
+    20,
+    21,
+    22,
+    23,
+    24,
+    25,
+    26,
+    27,
+    null,
   ])('when using jest version %i', jestVersion => {
     beforeEach(async () => {
-      detectJestVersionMock.mockReturnValue(jestVersion);
+      getJestVersionMock.mockReturnValue(jestVersion);
     });
 
     const allowedFunctions: string[] = [];
@@ -111,7 +139,7 @@ describe('the rule', () => {
         [26, 'jest.genMockFromModule', 'jest.createMockFromModule'],
       ] as const
     ).filter(deprecation => {
-      if (deprecation[0] > jestVersion) {
+      if (jestVersion && deprecation[0] > jestVersion) {
         allowedFunctions.push(deprecation[1]);
 
         return false;
@@ -125,11 +153,15 @@ describe('the rule', () => {
         'jest',
         'require("fs")',
         ...allowedFunctions.flatMap(func =>
-          generateValidCases(jestVersion, func),
+          generateValidCases(jestVersion ?? undefined, func),
         ),
       ],
       invalid: deprecations.flatMap(([, deprecation, replacement]) =>
-        generateInvalidCases(jestVersion, deprecation, replacement),
+        generateInvalidCases(
+          jestVersion ?? undefined,
+          deprecation,
+          replacement,
+        ),
       ),
     });
 
@@ -146,38 +178,4 @@ describe('the rule', () => {
       ),
     });
   });
-
-  describe('when there is an error in detecting the jest version', () => {
-    beforeEach(() => {
-      detectJestVersionMock.mockImplementation(() => {
-        throw new Error('oh noes!');
-      });
-    });
-
-    it('bubbles the error up', () => {
-      expect(() => {
-        const linter = new TSESLint.Linter();
-
-        /* istanbul ignore if */
-        if (usingFlatConfig) {
-          linter.verify('jest.resetModuleRegistry()', [
-            {
-              plugins: {
-                jest: { rules: { 'no-deprecated-functions': rule } },
-              },
-              rules: { 'jest/no-deprecated-functions': 'error' },
-            },
-          ]);
-
-          return;
-        }
-
-        linter.defineRule('no-deprecated-functions', rule);
-
-        linter.verify('jest.resetModuleRegistry()', {
-          rules: { 'no-deprecated-functions': 'error' },
-        });
-      }).toThrow('oh noes!');
-    });
-  });
 });

src/rules/no-deprecated-functions.ts

@@ -1,29 +1,11 @@
 import { AST_NODE_TYPES, type TSESTree } from '@typescript-eslint/utils';
 import {
-  type JestVersion,
+  type EslintPluginJestRuleContext,
   createRule,
-  detectJestVersion,
+  getJestVersion,
   getNodeName,
 } from './utils';
 
-interface ContextSettings {
-  jest?: EslintPluginJestSettings;
-}
-
-interface EslintPluginJestSettings {
-  version: JestVersion | string;
-}
-
-const parseJestVersion = (rawVersion: number | string): JestVersion => {
-  if (typeof rawVersion === 'number') {
-    return rawVersion;
-  }
-
-  const [majorVersion] = rawVersion.split('.');
-
-  return parseInt(majorVersion, 10);
-};
-
 export default createRule({
   name: __filename,
   meta: {
@@ -40,10 +22,9 @@ export default createRule({
   },
   defaultOptions: [],
   create(context) {
-    const jestVersion = parseJestVersion(
-      (context.settings as ContextSettings)?.jest?.version ||
-        detectJestVersion(),
-    );
+    // If jest version is not detected, assume latest
+    const jestVersion =
+      getJestVersion(context as EslintPluginJestRuleContext) || Infinity;
 
     const deprecations: Record<string, string> = {
       ...(jestVersion >= 15 && {

src/rules/utils/__tests__/detectJestVersion.test.ts

@@ -93,12 +93,10 @@ describe('detectJestVersion', () => {
     });
 
     describe('when the package.json is missing the version property', () => {
-      it('throws an error', () => {
+      it('returns null', () => {
         packageJsonFactory.mockReturnValue({});
 
-        expect(() => detectJestVersion()).toThrow(
-          /Unable to detect Jest version/iu,
-        );
+        expect(detectJestVersion()).toBeNull();
       });
     });
 
@@ -184,7 +182,7 @@ describe('detectJestVersion', () => {
   });
 
   describe('when jest is not installed', () => {
-    it('throws an error', () => {
+    it('returns null', () => {
       const projectDir = setupFakeProject({
         'package.json': { name: 'no-jest' },
         [`node_modules/${relativePathToFn}`]: compiledFn,
@@ -193,8 +191,8 @@ describe('detectJestVersion', () => {
 
       const { stdout, stderr } = runDetectJestVersion(projectDir);
 
-      expect(stdout).toBe('undefined');
-      expect(stderr).toContain('Unable to detect Jest version');
+      expect(stdout).toBe('null');
+      expect(stderr).toContain('');
     });
   });
 

src/rules/utils/detectJestVersion.ts

@@ -1,4 +1,19 @@
 import type { JSONSchemaForNPMPackageJsonFiles } from '@schemastore/package';
+import type { RuleContext } from '@typescript-eslint/utils/ts-eslint';
+
+interface ContextSettings {
+  [key: string]: unknown;
+  jest?: EslintPluginJestSettings;
+}
+
+interface EslintPluginJestSettings {
+  version: JestVersion | string;
+}
+
+export interface EslintPluginJestRuleContext
+  extends Readonly<RuleContext<never, []>> {
+  settings: ContextSettings;
+}
 
 export type JestVersion =
   | 14
@@ -22,7 +37,25 @@ export type JestVersion =
 
 let cachedJestVersion: JestVersion | null = null;
 
-export const detectJestVersion = (): JestVersion => {
+const parseJestVersion = (rawVersion: number | string): JestVersion => {
+  if (typeof rawVersion === 'number') {
+    return rawVersion;
+  }
+
+  const [majorVersion] = rawVersion.split('.');
+
+  return parseInt(majorVersion, 10);
+};
+
+export const getContextJestVersion = (
+  context: EslintPluginJestRuleContext,
+): JestVersion | null => {
+  return context.settings.jest?.version
+    ? parseJestVersion(context.settings.jest.version)
+    : null;
+};
+
+export const detectJestVersion = (): JestVersion | null => {
   if (cachedJestVersion) {
     return cachedJestVersion;
   }
@@ -35,13 +68,15 @@ export const detectJestVersion = (): JestVersion => {
       require(jestPath) as JSONSchemaForNPMPackageJsonFiles;
 
     if (jestPackageJson.version) {
-      const [majorVersion] = jestPackageJson.version.split('.');
-
-      return (cachedJestVersion = parseInt(majorVersion, 10));
+      return (cachedJestVersion = parseJestVersion(jestPackageJson.version));
     }
   } catch {}
 
-  throw new Error(
-    'Unable to detect Jest version - please ensure jest package is installed, or otherwise set version explicitly',
-  );
+  return null;
+};
+
+export const getJestVersion = (
+  context: EslintPluginJestRuleContext,
+): JestVersion | null => {
+  return getContextJestVersion(context) || detectJestVersion();
 };